Food product and method of preparing the same



April 17,, 1934. B|RD$EYE 1,955,484

FOOD PRODUCT AND METHOD OF PREPARING THE SAME Filed Feb. 1, 1930 F1 gzil Patented Apr. 17, 1934 FOOD PRODUCT AND METHOD OF PREPARING THE SAME Glarence Birdseye, Gloucester, Mass, assignor to Frosted Foods Company, Inc., Dover, Del, a corporation of Delaware Application February 1, 1930, Serial No. 425,094

3 Claims. (CI. 99-14) This invention relates to improvements in prebeing wasted as it usually is when available only paring frozen vegetable products for use by the in domestic quantities. consumer and includes within its scope the novel My invention may be applied with particular food product so produced. advantage to the preparation of frozen consumer 5 Certain vegetable products have heretofore packages of vegetable product in that the moist. 60

been preserved by freezing; for example, strawsoft and partially sterilized pre-cookecl food stuff berries with added sugar, have been packed and may be conveniently and compactly shaped and frozen in barrels or casks and sweet corn has been packed in containers, such as cartons, wrapped frozen in blocks of ice, but by none of the freezand substantially hermetically sealed therein and ing processes heretofore practiced has it proved then, while thus protected from contamination, 65. commercially practicable to supply the consumfrozen into solid blocks particularly well adapted er with vegetables preserved by freezing and for handling, storage and distribution under packaged for distribution as frozen units of concommercial conditions. In another aspect, acvenient size. I have discovered that many vegecordingly, my invention consists in a method of table products may be so treated and prepared packaging vegetable products which consists in 70' by first subjecting them to a pre-cooking step, pre-cooking the raw product, enclosing and sealthen freeing from surplus water and finally ing the pre-cooked product in a container and packaging and freezing in cartons. In one then freezing the product in its container. The aspect, accordingly, my invention consists in an frozen package thus produced is also believed to improvement in preparing vegetable products be novel and constitutes a feature of the inven- 75 for storage, distribution and use characterized tion. by a pre-cooking step followed by packaging and It may be pointed out that the pre-cooking and freezing in this manner. freezing steps which characterize the method of The extent or degree of the pre-cooking step my invention both contribute to break down the is of secondary importance only and may be cellular structure of the raw vegetable product, as so carried to apoint determined by the requirements is necessary in rendering it fit for human con- Of the Particular raw p du t eing dealt with sumption. When such vegetables as carrots, turand the manner in which it is to be used. It is nips and the like are prepared by cooking alone, desirable generally, however, in the pre-cooking a considerable per cent of the cooking time is restep to effect a modification of the product in quired to break down the cellular structure. In 8,) a number of different respects. In the first place, softer vegetables, such as asparagus, spinach and the product may be sterilized or partially sterilthe like, a smaller proportion of the cooking time ized and the danger of bacteriological deteriorais required for this purpose, but in all cases this tion thus practically'eliminated. In the second factor must be reckoned with as requiring both place, objectionable oxidation of the product may time and energy in the form of heat. The ef- 90 be prevented in a marked degree, such oxidation, feet of freezing or quick-freezing a vegetable for example, as that occurring in an exposed product is also largely to break down the cellusurface of raw apple or banana. Then, by renlar structure, since the cells are relatively nondering the product pliable and removing its natelastic and the expansion of their contents in ural resiliency, the packing thereof in marketfreezing is sufficient to rupture the cells. It will 95 able packages is greatly facilitated and the dense be apparent that the two steps supplement each and compact mass of the pre-cooked product other in effectively breaking down the cellular may be frozen with greatest economy and resists structure of the vegetable with a resulting econothawing' with best advantage. my in the time and heat required for cooking. By the i p p s of y t on, more- The freezing step is, therefore, utilized to double 10o over, a large quantity of moisture is removed advantage in that it not only preserves the vegefrOm the product before P ng, rather than table product and solidifies the package but perafter distribution as is now the case. This is forms mechanical work on the product. A prodadvantageous from the standpoint of economy uct thus prepared reaching the consumer requires since it is thus unnecessary to freeze this superonly to be warmed or slightly cooked to render it 13.)

fiuous moisture or to transport its additional edible. weight in the product. Incidentally, if the prod- .By subjecting a vegetable product to the sup- 11015 is Dre-Cooked in large quantities under mplementary steps of precooking and freezing, it mercial conditions, the extracted moisture may is possible to reduce the cooking time by one-half be concentrated and profitably used instead of to two-thirds as compared with that otherwise llO required, thus effecting an important econ 7 nd rendering possible the preparation of roduct by the consumer with the assistance of ited Vegel iilted amount of heat or heat for l. 1 -iod. i-iioreover, by subjecting our tables to different degrees or" pie-cooking, they may all be brought to a condition wherein the same amount of further cooking will suffice to prepare them for the table, with all the resulting convenience to the housewife.

Still another advantage of my invention. lies in the fact that upon thawing, the frozen product returns to a cooked or semi-cooked condition and not an uncooked condition as heretofore. The result is that the product may be kept in good condition before serving for a much longer time than would be otherwise expedient. Finally, inasmuch as the product reaches the consumer as cooked product, the purchaser does not insist upon the fresh appearance which would .oe otherwise reior th e and by 'ention may be prac p l good advantage in preparing spinach sinner packages. Fresh spinach includes unt of moisture which is extracted in co ng and Meyer reaches the consum inoval at an early stage in the process or its preparation is of decided economical advantage. ly on account of this moisture, the bulk of spinach is very great compared to its volume Men prepared for consumption.

In practicing the method of my invention, raw spinach is first cleaned and the large 5 sections removed. time or sufiiciently to remove its naturai resiliency, extract the superfluous moisture anc. render it soft and pliable. In this step the spinach is also substantially sterilized and its volume re-- duced to a striking degree.

The pro-cooked or partially cooked spinach is then drained of free water and thus pr d to be conveniently packed in a pasteboard c other container without excess Water. On account of its soft and pliable condition, it will pack compactly and conform itself in the mass exactly to the shape of the carton with a minimum of voids or air spaces.

When the carton is substantially full, it may be closed. wrapped in a. moisture and vapor-proof material, such as cellophane, and sealed substantially hermetically. It will be noted that M tiiB pie-cooked spinach has thus been protected from bacteriological deterioration and by promptly sealing it as above outlined it is also protected irom exterior contamination.

The sealed carton with its contents may next be frozen, preferably quick-frozen, and thus conr' rtod into solid block ready for shipment or The freezing step he carried out oparatus cMaple, as 73,081, dated an t con 19 is shown inrerp beti. een 1 heat-conductive bands ti"- and 32 wr perature of approximately .-0 F. by refrigerated calcium chloride brine supplied by the pipes er and L3. The heat of the carton and its contents is thus removed by direct conduction and under the conditions suggested the sealed carton with its soft and yielding contents is converted in about 20 minutes to a solid brick.

The complete consumer package is shown in Fig. 2, wherein the pre-cooked spinach 12 is shown as completely filling the carton 10 which is of cardboard, preferably treated with paraffin to render it waterproof. The carton is wrapped and sealed in a thin transparent covering of moisture and vapor-proof cellophane 14 which is efiective to prevent evaporation from the kept in storage for long per deterioration. i lhen the consumer desires to use its contents, the carton is opened and the frozen block of spinach rendered edible by thawing and boiling for approximately 5 minutes. It will be understooo that the breaking down of the cellular structure of the spinach, due to the ireczin .:.ces the cooking:

' d to render to subie s" 305. any as new and .lesire to tters Patsecure by T method of preparing a mark table a ole product, which consists in artially cooking the raw vegetable to remove a portion of its moisture content, render it pliable and compact, and partially break down its celcture, then packing the partially cooke in a carton without excess water, and nally freezing "he packed carton in a manner maintaining its shape and converting it into a solid block.

. The method of preparing marketable package of spinach, which consists in partially cooking the raw spinach to remove a portion of its moisture content, render it pliable and coinpact, and partially break down its cellular structure, then completely filling a carton the partially cooked spinach, closing and se ng the carton, and finally quick-freezing the filled carton from opposite sides thereby converting it into a solid block and at the same time further brcaling down the cellular structure or" the spinach contained therein.

3. A frozen marketable package comprising a carton substantially hermetically sealed and completely filled with a frozen cornpact' vegetable product, not more than partially cooked, 1,- containing less than its natural moisture content L L and having its cellular structure partially broken down, the carton and its contents forming a solid frozen unit adapted for storage and tran por 

